An electrocardiogram (also known as an ECG or EKG) is a very useful tool in your veterinarian’s arsenal for assessing your pet’s heart rhythm and rate. It can also be useful in identifying heart enlargement, which is present in many kinds of heart disease.
EKGs are a graph of the heart’s electrical current. The heart’s electrical activity creates a current that radiates through the surrounding tissue. This electric activity is picked up by electrodes placed in three locations on your pet’s body, and the information is transmitted to a monitor. I’m sure that you are familiar with this type of monitor, as it is present in almost every hospital scene on the big screen and small screen alike. The EKG is the machine beeping rhythmically with each heartbeat or giving one long ominous beep to signify that a beloved character’s heart has stopped beating.
EKGs are often performed prior to surgery. The procedure itself is painless, non-invasive, and extremely well tolerated. Pets are placed on their side, and three small clips are attached to their skin to measure the heart’s electrical activity. The whole test takes only a few minutes, and the results can be read either in the clinic by the veterinarian, or they can be transmitted to a cardiologist for review.
EKGs allow us to evaluate both the heart rate and its rhythm. Heart rate abnormalities include tachycardia (elevated heart rate), bradycardia (decreased heart rate) and fibrillation (rapid, unsynchronized impulses). Arrhythmias occur when the normal rhythm of the heart is disrupted. Most arrhythmias are harmless, but some can be life threatening. Failure of the heart to maintain a rhythmic pace can mean that blood does not get pumped effectively through the body.
EKGs are not typically performed in healthy pets as part of a routine exam, except in the case of pets undergoing a pre-anesthetic work-up. Dogs and cats with cardiac disease will likely have many EKGs to assess heart size and function. Often EKGs are used in conduction with x-rays and echocardiograms (an ultrasound of the heart) to paint a complete picture of how the heart is functioning.
If your veterinarian recommends an EKG for your pet, don’t fret. They are quick and painless, and the information they give will guide your pet’s treatment or anesthetic protocol, leading to a healthier pet!